1 /* $OpenBSD: uvm_object.c,v 1.8 2014/05/08 20:08:50 kettenis Exp $ */ 2 3 /* 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Mindaugas Rasiukevicius. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * uvm_object.c: operate with memory objects 34 * 35 */ 36 37 #include <sys/param.h> 38 #include <sys/proc.h> /* XXX for atomic */ 39 40 #include <uvm/uvm.h> 41 42 /* We will fetch this page count per step */ 43 #define FETCH_PAGECOUNT 16 44 45 /* 46 * uvm_objinit: initialise a uvm object. 47 */ 48 void 49 uvm_objinit(struct uvm_object *uobj, struct uvm_pagerops *pgops, int refs) 50 { 51 uobj->pgops = pgops; 52 RB_INIT(&uobj->memt); 53 uobj->uo_npages = 0; 54 uobj->uo_refs = refs; 55 } 56 57 #ifndef SMALL_KERNEL 58 /* 59 * uvm_objwire: wire the pages of entire uobj 60 * 61 * => caller must pass page-aligned start and end values 62 * => if the caller passes in a pageq pointer, we'll return a list of 63 * wired pages. 64 */ 65 66 int 67 uvm_objwire(struct uvm_object *uobj, voff_t start, voff_t end, 68 struct pglist *pageq) 69 { 70 int i, npages, left, error; 71 struct vm_page *pgs[FETCH_PAGECOUNT]; 72 voff_t offset = start; 73 74 left = (end - start) >> PAGE_SHIFT; 75 76 while (left) { 77 78 npages = MIN(FETCH_PAGECOUNT, left); 79 80 /* Get the pages */ 81 memset(pgs, 0, sizeof(pgs)); 82 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 83 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 84 PGO_ALLPAGES | PGO_SYNCIO); 85 86 if (error) 87 goto error; 88 89 for (i = 0; i < npages; i++) { 90 91 KASSERT(pgs[i] != NULL); 92 KASSERT(!(pgs[i]->pg_flags & PG_RELEASED)); 93 94 #if 0 95 /* 96 * Loan break 97 */ 98 if (pgs[i]->loan_count) { 99 while (pgs[i]->loan_count) { 100 pg = uvm_loanbreak(pgs[i]); 101 if (!pg) { 102 uvm_wait("uobjwirepg"); 103 continue; 104 } 105 } 106 pgs[i] = pg; 107 } 108 #endif 109 110 if (pgs[i]->pg_flags & PQ_AOBJ) { 111 atomic_clearbits_int(&pgs[i]->pg_flags, 112 PG_CLEAN); 113 uao_dropswap(uobj, i); 114 } 115 } 116 117 /* Wire the pages */ 118 uvm_lock_pageq(); 119 for (i = 0; i < npages; i++) { 120 uvm_pagewire(pgs[i]); 121 if (pageq != NULL) 122 TAILQ_INSERT_TAIL(pageq, pgs[i], pageq); 123 } 124 uvm_unlock_pageq(); 125 126 /* Unbusy the pages */ 127 uvm_page_unbusy(pgs, npages); 128 129 left -= npages; 130 offset += (voff_t)npages << PAGE_SHIFT; 131 } 132 133 return 0; 134 135 error: 136 /* Unwire the pages which have been wired */ 137 uvm_objunwire(uobj, start, offset); 138 139 return error; 140 } 141 142 /* 143 * uobj_unwirepages: unwire the pages of entire uobj 144 * 145 * => caller must pass page-aligned start and end values 146 */ 147 148 void 149 uvm_objunwire(struct uvm_object *uobj, voff_t start, voff_t end) 150 { 151 struct vm_page *pg; 152 off_t offset; 153 154 uvm_lock_pageq(); 155 for (offset = start; offset < end; offset += PAGE_SIZE) { 156 pg = uvm_pagelookup(uobj, offset); 157 158 KASSERT(pg != NULL); 159 KASSERT(!(pg->pg_flags & PG_RELEASED)); 160 161 uvm_pageunwire(pg); 162 } 163 uvm_unlock_pageq(); 164 } 165 #endif /* !SMALL_KERNEL */ 166